Queue dApp signing requests

[clauxx]

Feature Issue

User Story

As a user, I want to be able to approve requests in a sequence, so that they don't interfere with the request that is currently shown.

Description

In case the user receives signing/connection requests while they're reviewing another request, they should be queued and shown right after the current one is dismissed or approved.

Design link

Acceptance Criteria

• The user should see a toast if they receive a dApp request while they're already on a dApp request screen
• The user should get the next dApp request when the current one was approved/dismissed.

Notes